<template>
  <el-breadcrumb class="app-breadcrumb" separator="/">
    <transition-group name="breadcrumb">
      <el-breadcrumb-item v-for="(item, index) in breadcrumbs" :key="item.path">
        <span v-if="item.redirect === 'noredirect' || index == breadcrumbs.length-1" class="no-redirect">{{ item.meta.title }}</span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    </transition-group>
  </el-breadcrumb>
</template>

<script lang="ts">
import { Component, Vue, Watch } from 'vue-property-decorator';
import { RouteRecord } from 'vue-router';
import pathToRegexp from 'path-to-regexp';

@Component
export default class Breadcrumb extends Vue {
  private breadcrumbs: RouteRecord[] = [];

  private created() {
    this.getBreadcrumb();
  }

  @Watch('$route')
  private onRouteChange() {
    this.getBreadcrumb();
  }

  private getBreadcrumb() {
    let matched = this.$route.matched.filter((item) => item.name);
    const first = matched[0];
    if (first && first.name !== 'dashboard') {
      matched = [{ path: '/dashboard', meta: { title: 'Dashboard' }} as RouteRecord].concat(matched);
    }
    this.breadcrumbs = matched.filter((item) => {
      return item.meta && item.meta.title && item.meta.breadcrumb !== false;
    });
  }

  private pathCompile(path: string) {
    // To solve this problem https://github.com/PanJiaChen/vue-element-admin/issues/561
    const { params } = this.$route;
    const toPath = pathToRegexp.compile(path);
    return toPath(params);
  }

  private handleLink(item: any) {
    const { redirect, path } = item;
    if (redirect) {
      this.$router.push(redirect);
      return;
    }
    this.$router.push(this.pathCompile(path));
  }
}
</script>

<style lang="scss" scoped>
  .app-breadcrumb.el-breadcrumb {
    display: inline-block;
    font-size: 14px;
    line-height: 50px;
    margin-left: 10px;

    .no-redirect {
      color: #97a8be;
      cursor: text;
    }
  }
</style>
